Black workers at a Cardinal Health warehouse facility in California endured a hostile work environment because of their race, a lawsuit filed May 21 alleges.

Their non-black co-workers used the n-word verbally and in graffiti in the warehouse restrooms, the Equal Employment Opportunity Commission says in the complaint filed with the U.S. District Court for the Central District of California.

The men’s room, women’s room, and temporary restrooms were all defaced with “racially derogatory graffiti” that included the n-word, the EEOC says.

The workers complained to their employment agency, AppleOne, and to Cardinal Health, but prompt remedial action wasn’t taken,...